EP0720199B1 - Field emission microcathode array devices - Google Patents

Field emission microcathode array devices Download PDF

Info

Publication number
EP0720199B1
EP0720199B1 EP95120076A EP95120076A EP0720199B1 EP 0720199 B1 EP0720199 B1 EP 0720199B1 EP 95120076 A EP95120076 A EP 95120076A EP 95120076 A EP95120076 A EP 95120076A EP 0720199 B1 EP0720199 B1 EP 0720199B1
Authority
EP
European Patent Office
Prior art keywords
field emission
apertures
main face
aperture
electrodes
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP95120076A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0720199A1 (en
Inventor
Keiichi Betsui
Hiroshi Inoue
Shin'ya Fukuta
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu Ltd
Original Assignee
Fujitsu Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP1178691A external-priority patent/JP2638315B2/ja
Application filed by Fujitsu Ltd filed Critical Fujitsu Ltd
Publication of EP0720199A1 publication Critical patent/EP0720199A1/en
Application granted granted Critical
Publication of EP0720199B1 publication Critical patent/EP0720199B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
    • H01J9/02—Manufacture of electrodes or electrode systems
    • H01J9/022—Manufacture of electrodes or electrode systems of cold cathodes
    • H01J9/025—Manufacture of electrodes or electrode systems of cold cathodes of field emission cathodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
    • H01J1/02—Main electrodes
    • H01J1/30—Cold cathodes, e.g. field-emissive cathode
    • H01J1/304—Field-emissive cathodes
    • H01J1/3042—Field-emissive cathodes microengineered, e.g. Spindt-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J3/00—Details of electron-optical or ion-optical arrangements or of ion traps common to two or more basic types of discharge tubes or lamps
    • H01J3/02—Electron guns
    • H01J3/021—Electron guns using a field emission, photo emission, or secondary emission electron source
    • H01J3/022—Electron guns using a field emission, photo emission, or secondary emission electron source with microengineered cathode, e.g. Spindt-type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/123—Flat display tubes
    • H01J31/125—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection
    • H01J31/127—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection using large area or array sources, i.e. essentially a source for each pixel group

Definitions

  • the present invention relates to field emission microcathode array devices for use, for example, in vacuum microdevices such as very small microwave vacuum tubes and display elements.
  • FIGS. 1(A) and 1(B) of the accompanying drawings illustrate a structure of a field emission microcathode, Fig. 1(A) being a perspective view and Fig. 1(B) being a sectional view.
  • a substrate 1' is made of, for example, a semiconductor.
  • a cone 2' serving as an emitter is formed on the substrate 1'.
  • a tip 20' of the cone 2' is surrounded by a gate electrode 30.
  • the substrate 1' is separated from the gate electrode 30 by a gate insulation film (not shown).
  • a gate opening 3 is formed around the tip 20' of the cone 2'. Operational characteristics of this field emission microcathode are mainly determined by the radius Rg of the gate opening 3, the height Ht of the cone 2', and the thickness Hg of the gate insulation film.
  • the semiconductor substrate 1' serves as a cathode electrode.
  • This substrate may be made of insulation material and a cathode electrode made of a conductive film may be disposed between the substrate and the cone.
  • these elements are made several micrometers or smaller in size by photolithography which is known in the field of semiconductor ICs.
  • the tip 20' of the cone 2' emits electrons. Namely, the cone 2' acts as a field emission microcathode.
  • a plurality of cones may be arranged in an array on a single substrate.
  • Figures 2(A) and 2(B) are examples of such a field emission microcathode array device for use in a display, Fig. 2(A) being a sectional view showing part of the display and Fig. 2(B) a diagram for explaining a method of driving the display.
  • the field emission microcathode array device 50' comprises many field emission microcathodes (electrodes) formed on a substrate 1'.
  • the microcathodes may be arranged two-dimensionally, or in longitudinal and lateral rows to form an X-Y matrix on the substrate 1'.
  • the field emission microcathode array device itself is already known. It may be made in sizes and pitches disclosed by the present inventors (Institute of Electronics, Information and Communication Engineers of Japan, Autumn National Convention, 1990, SC-8-2, 5-28-2).
  • a transparent substrate 10 made of, for example, glass.
  • Anodes 12 are formed on the lower face of the substrate 10.
  • Each of the anodes 12 is made of an ITO (In 2 O 3 -SnO 2 ) film having a thickness of 200 to 300 nm and an area of 100 x 100 ⁇ m.
  • a pitch between the adjacent anodes 12 is about 30 ⁇ m.
  • a fluorescent dot 11 smaller than the anode 12 is disposed on each of the anodes 12.
  • the dot 11 is made of, for example, a ZnO:Zn film having a thickness of 2 ⁇ m. Each dot 11 forms a pixel.
  • the substrates 1' and 10 are spaced apart from each other by a distance of about 200 ⁇ m, to form a display panel 100.
  • the display panel 100 is driven by a control circuit (an anode selection circuit) 200 shown in Fig. 2(B).
  • the anode selection circuit 200 is connected to the anodes 12.
  • a gate power source 260 applies a gate voltage so that the cones 2' simultaneously emit electrons, which are specifically attracted by a specific one of the anodes 12 that are selected by the anode selection circuit 200.
  • the electrons attracted by the specific anode permit the fluorescent dot 11 on the anode 12 in question to emit light.
  • the anode selection circuit 200 properly selects an optional anode 12, to which a positive potential is applied to allow the fluorescent dot 11 on the anode 12 in question to emit light, thus driving the display.
  • Figures 3(A) to 3(C) show a previously-considered arrangement of a field emission microcathode array device, where Fig. 3(A) is a perspective view, Fig. 3(B) a partially enlarged view, and Fig. 3(C) a sectional view along a line X-X of Fig. 3(A).
  • This device may be considered to include an array of electrodes, each of which electrodes projects from a main face of a substrate of the device, and also to include a gate electrode portion arranged so as to be opposed to but spaced from the said main face and formed with apertures that are in register respectively with the said electrodes.
  • the substrate 1 is made of glass.
  • a cathode 6 is formed on the substrate 1, and an insulation film 7 is formed on the cathode 6.
  • Many cones (electrodes) 2 are two-dimensionally formed in the insulation film 7.
  • a gate electrode 30 having gate openings 3 is laminated such that each opening 3 surrounds a tip 20 of a corresponding cone 2, to thereby form a field emission microcathode array device 50'.
  • the cones 2 are two-dimensionally arranged over the substrate 1. They may be arranged in longitudinal and lateral rows to form an X-Y matrix for each pixel (IEEE Trans. on Electron Device, Vol. 36, p. 225, 1989).
  • the cone-shaped electrodes (microcathodes), each having a diameter of several micrometers, of the array device 50' may be arranged at intervals of several micrometers, so that several hundreds of microcathodes can be arranged for each pixel to form an area of about 100 x 100 ⁇ m. This produces a bright screen and provides good redundancy against unevenness in brightness caused by differences in the characteristics of individual microcathodes.
  • the substrate 1 is a glass plate of, for example, 1.1 mm thickness.
  • the cathode 6 made of, for example, a Ta film having a thickness of 100 nm is formed by sputtering.
  • the insulation film 7 made of, for example, an SiO 2 film of 1000 nm thickness is disposed over the cathode 6.
  • the gate electrode 30 with a film of Cr, Ta, or Mo having a thickness of about 150 nm by a known method.
  • the openings 3 are formed on the gate electrode film 30, and holes for cones are formed on the insulation film 7. Thereafter, Mo, for example, is obliquely deposited on the cathode 6 exposed at the bottoms of the holes, thereby forming cones 2 (J. Appl. Phys., Vol. 39, p. 3504, 1968).
  • each opening 3 of the gate electrode 30 must correctly agree with the centre of the tip of a corresponding cone 2 according to a previously-considered fabrication method. What is important is the distance between the gate electrode and the tip of the cone. If the distance satisfies certain criteria, a sufficient emission current will be obtained. If the distance is not within the criteria, the emission current will be impractically low. Namely, the diameter of each gate opening or the distance between the tip of the cone and the gate electrode must be strictly controlled.
  • Figure 5 shows a relationship between a gate voltage Vg and an emission current Ie for three different values of the gate opening diameter.
  • an ordinate represents the discharge current Ie
  • an absc issa the gate voltage Vg.
  • a curve (1) represents the characteristics of a field emission cathode with a middle-sized gate opening 3b
  • a curve (2) represents the characteristics of a field emission cathode with a small-sized gate opening 3
  • a curve (3) represents the characteristics of a field emission cathode with a large-sized gate opening 3a.
  • An optimum radius of the gate opening is Rgo. If the actual size of any gate opening is larger or smaller than the optimum size, it produces a very small emission current. Namely, a sufficient emission current will not be obtained if the radius of the gate opening is different from the optimum value.
  • the area and shape of each opening of the gate electrode in the field emission microcathode array device must be strictly controlled during fabrication by precise designing and process control. Even under such strict control, the diameter of openings of the gate electrode may fluctuate for various reasons. In this case, the production costs of the microcathode array device may increase and the production yield may decrease.
  • a field emission microcathode array device including an array of electrodes, each of which electrodes projects from a main face of a substrate of the device, and also including a gate electrode portion arranged so as to be opposed to but spaced from the said main face and formed with apertures that are in register respectively with the said electrodes; characterised in that the said apertures formed at preselected different respective locations differ from one another dimensionally in a preselected manner.
  • the electrodes are in the form of cones, each having a base on the said main face and a sharp tip surrounded by one of the said apertures for emitting electrons by field emission when the device is in use; and the apertures are circular and are formed with at least two different diameters.
  • the gate electrode apertures that greatly influence electron beam emission characteristics are prepared in, for example, three sizes (large, middle, and small) and are intermingled.
  • the large-sized gate apertures will have an optimum radius for field emission purposes if each aperture is inadvertently made with a reduced radius due to fabrication errors.
  • the small-sized gate apertures will have the optimum radius.
  • a field emission microcathode device including an elongate electrode, which projects from a main face of a substrate of the device and has a sharp linear edge, and also including a gate electrode portion arranged so as to be opposed to but spaced from the said main face and formed with an aperture that surrounds the said linear edge of the said electrode; characterised in that the width of the aperture varies along the length of the said edge in a preselected manner.
  • a field-emission microcathode array device including a plurality of elongate electrodes arrayed over a main face of a substrate of the device, each electrode projecting from the said main face and having a sharp linear edge, and also including a gate electrode portion arranged so as to be opposed to but spaced from the said main face and being formed with a plurality of such apertures each surrounding the linear edge of a corresponding one of the electrodes, characterized in that the width of each aperture varies along the length of the edge it surrounds in a preselected manner.
  • a method of producing a device embodying the aforesaid first aspect of the invention including the steps of: forming a predetermined masking pattern on the said substrate, which pattern includes, at the said preselected different respective locations, aperture-defining portions that differ from one another dimensionally in a predetermined manner; etching exposed parts of the substrate to form a recessed substrate surface providing the said main face and having the said electrodes projecting therefrom at the said locations; forming a spacing layer on the said recessed substrate surface; forming an electrically-conductive layer on the spacing layer, the said aperture-defining portions protruding through the said electrically-conductive layer at the said locations; and etching away the said aperture-defining portions to form the said gate electrode portion in the said electrically-conductive layer, so that the said apertures that differ from one another dimensionally in a preselected manner are formed at the said preselected different respective locations.
  • a field emission microcathode array device embodying the present invention may be made as described hereinafter.
  • Figures 6(1) to 6(6) show examples of fabrication processes. These processes form a cold cathode cone by isotropic etching of a silicon substrate (Mat. Res. Soc. Symp., Vol. 76, p. 25, 1987).
  • an SiO 2 film 500 of uniform thickness is formed on a silicon substrate 1 by thermal oxidation.
  • the SiO 2 film 500 is etched by photolithography into a predetermined shape and size to form an SiO 2 mask pattern 500'.
  • Fig. 6(3) only silicon of the substrate is isotropically etched in a mixture of HF and HNO 3 , to form a cone 2 serving as an emitter under the SiO 2 mask pattern 500'.
  • SiO 2 is deposited or sputtered over the processed substrate, to form an SiO 2 film 510 such that a space is formed around the cone 2.
  • a gate electrode film 310 made of, for example, Mo is uniformly formed. At this time, at least part of the side faces of the SiO 2 mask pattern 500' is exposed.
  • etching with HF is carried out to remove all of the SiO 2 mask pattern 500' and part of the SiO 2 film 510. As a result, an opening 3 is formed, and the cone 2 is exposed in the space. This completes the formation of a field emission microcathode on the silicon substrate.
  • an array of cathodes can be formed on a substrate by employing a proper mask and photolithography technique.
  • each cone 2 and a corresponding opening 3 formed on the gate electrode 30 are very important.
  • the tip of the cone 2 must agree with the centre of the opening 3.
  • One problem in achieving such agreement is that the diameter or the width of a circular or rectangular gate electrode opening may fluctuate depending on fabrication conditions. This fluctuation is unavoidable even with strict designing. If the diameter of each opening 3 of the gate electrode 30 fluctuates, a required emission current may not be obtained.
  • operational characteristics of the field emission microcathode are determined by the radius Rg of the gate electrode opening 3, the height Ht of the cone 2, and the thickness Hg of the gate insulation film.
  • an ordinate represents an emission current Ie, and an abscissa a gate voltage Vg.
  • a curve (1) in Fig. 5 represents a typical example with the diameter of the opening 3 being equal to a required value (i.e. 2Rgo).
  • a voltage is applied and increased with the cone 2 being negative and the gate 30 positive, the top 20 of the cone 2 suddenly emits electrons at a certain threshold voltage.
  • an operational emission current of Ieo is obtained.
  • any opening 3 of the gate electrode is larger than the required value as in the case of a curve (3) in Fig. 5, or smaller as in the case of a curve (2), an emission current obtained from the same gate voltage decreases significantly to an unacceptably low level.
  • the above problem may not be unduly serious when the number of cones 2 is small, because the height Ht of the cone 2 and the diameter 2Rg of the gate electrode opening 3 are each several micrometers or smaller.
  • the above problem may arise in the processes of deposition, exposure, etching, etc.
  • the size of the gate electrode opening is larger or smaller than the optimum value, an emission current will be very small. Namely, a sufficient emission current is not obtained if the diameter of the gate electrode opening deviates from the optimum value. As a result, the production yield of field emission microcathode array devices having required characteristics deteriorates.
  • a field emission microcathode array device comprises a substrate 1 on which cones 2 each having a sharp tip are formed, and gate electrode openings 3 each surrounding the tip 20 of a corresponding cone 2.
  • the tip 20 of each cone 2 emits electron beams because of field emission.
  • the gate electrode openings 3 have different sizes and are intermingled over the substrate.
  • Another field emission microcathode array device comprises a substrate on which an elongate electrode (wedge) 4 having a sharp blade-like edge (linear edge) 40 is formed, and a groove-like gate electrode opening 5 surrounding the edge 40.
  • the blade-like edge 40 emits electron beams because of field emission.
  • the width of the gate electrode opening 5 varies along the edge 40.
  • a plurality of such field emission cathodes may be arranged in an array on the substrate.
  • Figure 7 shows the first embodiment.
  • this figure simply shows an arrangement of tips 20 of cones and gate electrode openings 3 that form a field emission microcathode array device 50a.
  • the openings 3 have three sizes. Namely, they are classified into large-sized openings 3a, middle-sized openings 3b, and small-sized openings 3c that cyclically appear.
  • This arrangement may be fabricated according to, for example, the processes explained with reference to Figs. 6 (1) to 6 (6).
  • the sizes and intervals of the openings 3 are selected according to requirements.
  • This embodiment positively forms the openings 3 having different sizes, which are selected based on a required size. It is preferable to prepare at least three opening sizes above and below the required size. It is possible to prepare more than three sizes.
  • the openings 3 having different sizes may be randomly distributed or somewhat regularly arranged on the gate electrode 30.
  • Figure 8 shows a previously-considered emitter structure for use in a field emission microcathode array device not embodying the present invention.
  • the Fig. 8 emitter (electrode) 4 is elongate and has a blade-like edge 40 which linearly emits electrons. Accordingly, a gate electrode opening 5 is shaped into a long thin groove having a width of 2Rg. This structure may be used for emitting a linear beam.
  • Figure 9 shows one arrangement of gate electrode openings in a field emission microcathode array device having such emitters. For simplicity, this figure simply shows the blade-like edges 40 and gate electrode openings 5 of the field emission microcathode array device 50'b. Each electrode is the same as shown in Fig. 8. This example emits electron beams in a wide area.
  • Fig. 9 can suffer from the same problem as that explained with reference to Fig. 5.
  • the second embodiment of the present invention, shown in Fig. 10, is intended to address this problem in the case of elongate electrodes.
  • Figure 10 schematically shows edge blades 40 and gate electrode openings 5 used in a field emission microcathode array device 50b according to the second embodiment of the invention.
  • each opening 5 is tapered along the length of the blade-like edge 40 of the corresponding electrode. At optimum width portions of the opening, electron beams are self-selectively emitted.
  • each opening 5 by making the width of each opening 5 irregular along the length of the emitter edge 40, it can be ensured that optimum width portions of each opening 5 will self-selectively emit electrons. This is true for every electrode so that electron beams are stably emitted from a large area.
  • the Fig. 10 embodiment relates to an array of emitter edges.
  • the present invention is also applicable in another embodiment to a single long linear field emission cathode.
  • embodiments of the invention effectively provide large - middle -, and small-sized gate electrode openings 3 (5) and distribute them over the substrate. Even if the sizes of the openings fluctuate because of fabrication errors, some cones 2 or wedges 4 with their gate openings having an optimum spacing (optimum radius Rgo) may self-selectively emit electron beams. In this way, the embodiments can stably emit electron beams from a wide area or along a long line.
  • Non-impact printers such as laser printers using optical line beams are in wide use these days.
  • the laser printers require a device for guiding a light beam to many positions.
  • Methods of guiding a light beam to many positions include a light beam scanning method and an optical array method.
  • the optical array method arranges many light emitting elements such as laser diodes for corresponding optical points such as printing dots, respectively.
  • the optical array method contributes to high-speed low-noise printing.
  • the light beam scanning method scans an object with a light beam by rotating a light deflecting element such as a rotary polygon mirror and a hologram disk. This method is most widely used because it provides high resolution and a wide scanning angle.
  • a light source 610 such as a semiconductor laser emits a laser beam, which is converged by a convergent lens 604 such as a hologram lens into a predetermined diameter. At the same time, aberration of the beam is corrected.
  • the beam is then made incident on a hologram 602 formed on a hologram disk 601.
  • the hologram disk 601 is rotated by a motor 603. According to the rotation of the hologram disk 601, the incident beam is deflected by the hologram 602 in different directions. Accordingly, an outgoing beam 605 scans the surface of a photoconductor drum 300.
  • Other devices such as a charger, developing unit, and sheet feeding mechanism necessary for forming the electrostatic recording optical printer are not shown in Fig. 11 for the sake of simplicity.
  • the conventional optical array method for optical printers is inferior in brightness, resolution, and cost.
  • the light beam scanning method mentioned above must employ a precision motor and fine rotation control mechanism for rotary elements such as the rotary polygon mirror and hologram disk, to meet high-quality printing requirements. This may increase the size and cost of the apparatus.
  • an optical printer at least comprising a field emission cathode type optical head 100 including a fluorescent dot array and field emission microcathodes for emitting electron beams towards the fluorescent dot array, a control circuit 200 for turning on and off the optical head 100, and a photoconductor drum 300 having a photoconductor 301 on which a latent image is formed by the optical head 100 as it is turned on and off.
  • the optical head 100 includes a field emission microcathode array device, having either cone-type or edge-type field emission microcathodes (electrodes), embodying the present invention.
  • optical head 100 of a field emission microcathode array device embodying the present invention makes the optical printer compact, and provides low power consumption, a high degree of brightness, and a stable operation with no mechanically moving parts.
  • Figure 12 is a view showing an essential part of an optical printer employing such a device embodying the present invention.
  • Numeral 100 denotes a field emission cathode type optical head, a 150 an array of lenses such as equal magnification erect lenses, 300 a photoconductor drum, and 301 a photoconductor.
  • the optical head 100 comprises a fluorescent dot array (not shown) and a field emission microcathode array device (not shown) for emitting electron beams to the fluorescent dot array.
  • the optical head 100 is turned on and off by a control circuit (not shown), and the lens array 150 forms a latent image on the photoconductor 301 such as a ZnO:Zn film coated around the photoconductor drum 300.
  • Other devices such as a charger, developing unit, and sheet feeding mechanism necessary for the optical printer are not shown in the figure for the sake of simplicity, because these devices do not directly relate to the present invention.
  • Figure 13 shows generally the application to a printer of a field emission microcathode array device embodying the present invention.
  • Numeral 10 denotes a transparent substrate such as a glass substrate
  • 12 denotes anodes formed on the transparent substrate 10.
  • Each of the anodes 12 is made of, for example, an ITO (In 2 O 3 -SnO 2 ) film having a thickness of 200 to 300 nm and a size of about 50 ⁇ m.
  • the anodes 12 correspond to printing dots and are arranged at pitches of about 70 ⁇ m.
  • a fluorescent dot 11 which is smaller than the anode 12 and made of a ZnO:Zn film having a thickness of 2 ⁇ m.
  • Numeral 50 denotes the field emission microcathode array device including its substrate 1. At predetermined dimensions and pitches, the array device 50 is fabricated according to, for example, a method disclosed by the present inventors (Institute of Electronics, Information and Communication Engineers of Japan, Autumn National Convention, 1990, SC-8-2, 5-28-2).
  • the substrates 10 and 1 are spaced apart from each other by a distance of about 200 ⁇ m, to form a field emission cathode type head 100.
  • This head is arranged as shown in Fig. 12 and assembled with a control circuit, charger, developing unit, sheet feeding mechanism, etc., to form an optical printer.
  • Figure 14 shows circuitry for driving the device of Fig. 13.
  • Numeral 30 denotes a gate electrode and 200 a control circuit for turning on and off the field emission cathode type optical head 100.
  • the control circuit 200 is a gate selection circuit.
  • Numeral 250 denotes an anode power source, and 260 a gate power source.
  • the control circuit 200 selectively applies a gate voltage provided by the gate power source 260 to a specific cone 2 whose tip 20 then emits electrons.
  • the electrons are attracted by an anode 12 corresponding to the specific cone 2, the anode 12 being energized to positive potential by the anode power source 250. Accordingly, a fluorescent dot 11 formed on the anode 12 emits light.
  • the control circuit 200 may properly select a gate 30 to which a gate voltage is applied, to thereby emit light from an optional fluorescent dot 11.
  • each cone 2 serves as an emitter. With the diameter of each opening 3 being 2 ⁇ m and a pitch between the tips 20 of the cones 4 ⁇ m, electron beams are selectively emitted when a selecting gate voltage Vg of 80V and an anode voltage Va of 100 V are applied.
  • the head, together with the control circuit 200, can provide a high performance optical printer that achieves greater brightness than a printer employing conventional optical accessing methods.
  • Figure 15 is a schematic view showing parts of a printer having a field emission microcathode array device 50 embodying the invention that is arranged orthogonally to a fluorescent dot 11, so that electron beams may be emitted toward the fluorescent dot 11 from the side thereof. This construction improves light emission efficiency because the electron beams are not attenuated by the fluorescent dot 11.
  • Figure 16 is a schematic view showing parts of a printer in which a fluorescent dot 11 and a field emission microcathode array device 50 embodying the invention are formed on the same plane. This arrangement improves light emission efficiently and is easy to fabricate because the two elements are formed on the same plane. The arrangement of Fig. 16 improves production yield and decreases cost.
  • Figure 17 is a schematic view showing parts of another printer including a field emission microcathode array device embodying the invention.
  • the same reference numerals as those used for the previous figures represent like parts.
  • a field emission microcathode array 50 can be made very small by IC technology.
  • the tip of a cone 2 may have a size of about several micrometers.
  • the size of a fluorescent dot 11 corresponding to a printing dot has a size of several tens to hundreds of micrometers. it is possible, therefore, to arrange many cones 2 for each fluorescent dot 11, as shown in the figure. This arrangement can increase the number of electron beams for irradiating each fluorescent dot 11 and improve the redundancy and reliability of the printer as a whole.
  • Figure 18 shows circuitry for driving the device of Fig. 17.
  • the circuitry differs from the driving circuitry of Fig. 14 in that a control circuit 200 serves not as a gate selection circuit but as an anode selection circuit.
  • a gate voltage applied by a gate power source 260 causes electrons to be simultaneously emitted. The electrons are attracted by a specific anode 12 selected by the control circuit 200. The electrons then permit a fluorescent dot 11 on the anode 12 to emit light.
  • the anode 12, to which positive potential is applied, is properly selected by the control circuit 200, so that light may be emitted from a required fluorescent dot 11.
  • This device can provide a printer with greater performance and brightness compared with the conventional optical accessing methods.
  • a field-emission microcathode array device embodying the invention includes a gate electrode having openings of different sizes to expand the operation margin.
  • An optical printer may advantageously include a field-emission cathode type optical head that has field-emission microcathodes and fluorescent dots to serve as a light source of the printer, so as to make the printer compact, and provide low power consumption, a high degree of brightness, and a stable operation with no mechanically moving parts.
  • a field emission microcathode array device of the cone or edge-type embodying the present invention can serve to enhance these advantages of the optical head, simplify the structure, stabilise the performance and lower the cost of such a printer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
  • Cold Cathode And The Manufacture (AREA)
  • Electrodes For Cathode-Ray Tubes (AREA)
EP95120076A 1991-02-01 1992-01-31 Field emission microcathode array devices Expired - Lifetime EP0720199B1 (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
JP1178691 1991-02-01
JP1178691A JP2638315B2 (ja) 1991-02-01 1991-02-01 微小電界放出陰極アレイ
JP11786/91 1991-02-01
JP8485291 1991-04-17
JP8485291 1991-04-17
JP84852/91 1991-04-17
EP92300867A EP0497627B1 (en) 1991-02-01 1992-01-31 Field emission microcathode arrays

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
EP92300867.6 Division 1992-01-31
EP92300867A Division EP0497627B1 (en) 1991-02-01 1992-01-31 Field emission microcathode arrays

Publications (2)

Publication Number Publication Date
EP0720199A1 EP0720199A1 (en) 1996-07-03
EP0720199B1 true EP0720199B1 (en) 1999-06-23

Family

ID=26347304

Family Applications (2)

Application Number Title Priority Date Filing Date
EP95120076A Expired - Lifetime EP0720199B1 (en) 1991-02-01 1992-01-31 Field emission microcathode array devices
EP92300867A Expired - Lifetime EP0497627B1 (en) 1991-02-01 1992-01-31 Field emission microcathode arrays

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP92300867A Expired - Lifetime EP0497627B1 (en) 1991-02-01 1992-01-31 Field emission microcathode arrays

Country Status (4)

Country Link
US (1) US5489933A (enExample)
EP (2) EP0720199B1 (enExample)
KR (1) KR950001249B1 (enExample)
DE (2) DE69221174T2 (enExample)

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE69331709D1 (de) * 1993-01-19 2002-04-18 Leonid Danilovic Karpov Feldeffekt-emissionsvorrichtung
US5698933A (en) * 1994-07-25 1997-12-16 Motorola, Inc. Field emission device current control apparatus and method
JP3393935B2 (ja) * 1994-09-16 2003-04-07 株式会社東芝 ホログラムディスプレイ
US5587628A (en) * 1995-04-21 1996-12-24 Kuo; Huei-Pei Field emitter with a tapered gate for flat panel display
US5631518A (en) * 1995-05-02 1997-05-20 Motorola Electron source having short-avoiding extraction electrode and method of making same
JP3219263B2 (ja) * 1995-05-23 2001-10-15 キヤノン株式会社 発光装置
US5693235A (en) * 1995-12-04 1997-12-02 Industrial Technology Research Institute Methods for manufacturing cold cathode arrays
US5633561A (en) * 1996-03-28 1997-05-27 Motorola Conductor array for a flat panel display
US5903804A (en) * 1996-09-30 1999-05-11 Science Applications International Corporation Printer and/or scanner and/or copier using a field emission array
GB9626221D0 (en) 1996-12-18 1997-02-05 Smiths Industries Plc Diamond surfaces
GB2321335A (en) * 1997-01-16 1998-07-22 Ibm Display device
US6107728A (en) * 1998-04-30 2000-08-22 Candescent Technologies Corporation Structure and fabrication of electron-emitting device having electrode with openings that facilitate short-circuit repair
JP3139476B2 (ja) * 1998-11-06 2001-02-26 日本電気株式会社 電界放出型冷陰極
JP2000243218A (ja) * 1999-02-17 2000-09-08 Nec Corp 電子放出装置及びその駆動方法
JP3547360B2 (ja) * 1999-03-30 2004-07-28 株式会社東芝 フィールドエミッション型表示装置及びその駆動方法
US6429596B1 (en) 1999-12-31 2002-08-06 Extreme Devices, Inc. Segmented gate drive for dynamic beam shape correction in field emission cathodes
WO2002061789A1 (fr) * 2001-02-01 2002-08-08 Sharp Kabushiki Kaisha Dispositif d'emission electronique et affichage d'emission de champ
FR2828956A1 (fr) * 2001-06-11 2003-02-28 Pixtech Sa Protection locale d'une grille d'ecran plat a micropointes
KR20040034251A (ko) * 2002-10-21 2004-04-28 삼성에스디아이 주식회사 전계방출소자
KR100814822B1 (ko) 2006-09-05 2008-03-20 삼성에스디아이 주식회사 발광 장치, 이의 제조 방법 및 이 발광 장치를 포함하는액정 표시 장치
KR100814850B1 (ko) * 2006-10-02 2008-03-20 삼성에스디아이 주식회사 발광 장치 및 표시 장치
JP2008091279A (ja) * 2006-10-04 2008-04-17 Fuji Heavy Ind Ltd 発光装置
JP2010225297A (ja) * 2009-03-19 2010-10-07 Futaba Corp 冷陰極電子源の製造方法及び冷陰極電子源。
US20140146947A1 (en) * 2012-11-28 2014-05-29 Vanderbilt University Channeling x-rays
CN113174625B (zh) * 2021-04-26 2024-01-30 中国科学院微小卫星创新研究院 环状集束多孔发射针针尖的静态制备方法及装置

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2568394B1 (fr) * 1984-07-27 1988-02-12 Commissariat Energie Atomique Dispositif de visualisation par cathodoluminescence excitee par emission de champ
FR2607623B1 (fr) * 1986-11-27 1995-02-17 Commissariat Energie Atomique Source d'electrons polarises de spin, utilisant une cathode emissive a micropointes, application en physique des interactions electrons-matiere ou electrons-particules, physique des plasmas, microscopie electronique
FR2644287B1 (fr) * 1989-03-10 1996-01-26 Thomson Csf Procede de realisation de sources d'electrons du type a emission de champ et dispositifs realises a partir desdites sources
US5090932A (en) * 1988-03-25 1992-02-25 Thomson-Csf Method for the fabrication of field emission type sources, and application thereof to the making of arrays of emitters
US5170092A (en) * 1989-05-19 1992-12-08 Matsushita Electric Industrial Co., Ltd. Electron-emitting device and process for making the same
FR2661566B1 (fr) * 1990-04-25 1995-03-31 Commissariat Energie Atomique Laser compact a semi-conducteur du type a pompage electronique.
US5166709A (en) * 1991-02-06 1992-11-24 Delphax Systems Electron DC printer

Also Published As

Publication number Publication date
EP0497627A2 (en) 1992-08-05
EP0497627B1 (en) 1997-07-30
EP0497627A3 (enExample) 1994-03-09
DE69229485D1 (de) 1999-07-29
DE69221174D1 (de) 1997-09-04
US5489933A (en) 1996-02-06
DE69221174T2 (de) 1997-12-04
EP0720199A1 (en) 1996-07-03
KR950001249B1 (en) 1995-02-15
DE69229485T2 (de) 1999-10-21

Similar Documents

Publication Publication Date Title
EP0720199B1 (en) Field emission microcathode array devices
EP0434001B1 (en) Electron emission device and method of manufacturing the same
US5982091A (en) Flat display apparatus
US5508584A (en) Flat panel display with focus mesh
US6377002B1 (en) Cold cathode field emitter flat screen display
KR100201792B1 (ko) 전계 방출형 음극을 채용한 전자 디바이스
KR100597056B1 (ko) 대면적 ｆｅｄ 장치 및 그 제조 방법
WO1997015912A9 (en) Cold cathode field emitter flat screen display
JP3776314B2 (ja) 側方に分割された表面電極を含むスペーサを有するフラットパネル型ディスプレイの構造及び製造
US7067971B2 (en) Field emission element
KR20060104659A (ko) 전자 방출 소자
JPH04249025A (ja) 微小電界放出陰極アレイ　　　　
KR20060104655A (ko) 전자 방출 소자
KR100421750B1 (ko) 전자집속시스템 및 그것의 제조방법, 그리고 상기 전자집속시스템을 채용한 전자방출 디바이스
KR100464306B1 (ko) 전계방출표시소자및그스페이서제조방법
JPH04334855A (ja) 蛍光表示管
US6501229B2 (en) Graphic fluorescent display device
KR20060019888A (ko) 전자 방출 소자
US20070114911A1 (en) Electron emission device, electron emission display device using the same, and method for manufacturing the same
KR20020032208A (ko) 자기 집속형 게이트 전극 구조를 갖는 전계 방출 표시소자 및 그 제조 방법
KR19990002079A (ko) 전계방출표시소자용 스페이서의 제조방법
KR20020039699A (ko) 전계방출표시소자 및 그 제조방법
KR20020031820A (ko) 전계방출표시소자 및 그 제조방법
KR20010046795A (ko) 집속 렌즈를 갖는 전계 방출 표시 소자 및 그 제조방법
KR20000039173A (ko) 평판표시소자의 스페이서 제조방법

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AC Divisional application: reference to earlier application

Ref document number: 497627

Country of ref document: EP

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB NL

17P Request for examination filed

Effective date: 19961008

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

17Q First examination report despatched

Effective date: 19980602

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AC Divisional application: reference to earlier application

Ref document number: 497627

Country of ref document: EP

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB NL

REF Corresponds to:

Ref document number: 69229485

Country of ref document: DE

Date of ref document: 19990729

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20080130

Year of fee payment: 17

Ref country code: DE

Payment date: 20080124

Year of fee payment: 17

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20090115

Year of fee payment: 18

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20090131

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090801

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20090113

Year of fee payment: 18

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20090131

REG Reference to a national code

Ref country code: NL

Ref legal event code: V1

Effective date: 20100801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100801

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100201